Zak R, Rabinowitz M, Rajamanickam C, Merten S, Kwiatkowska-Patzer B
Basic Res Cardiol. 1980 Jan-Feb;75(1):171-8. doi: 10.1007/BF02001410.
Mitochondrial proliferation was studied in mature female rats following aortic constriction. Mitochondrial DNA (mtDNA) was assayed by a fluorometric method. The conditions for removal of nuclear DNA were developed and verified by assessment of molecular conformation of DNA. The mtDNA concentration in mitochondria increased 2,4, and 7 days post-operatively by 11, 72 and 117% respectively. Comparison with the rates of accumulation of cytochrome c, b, and aa3 indicates that during the first 24 hours of cardiac enlargement the inner mitochondrial components accumulate faster then mtDNA, but during the six subsequent days the rate of mtDNA increment far outstrips that of the cytochromes. These data indicate that the amount of available mtDNA templates is not the only factor regulating the transcriptional and translational processes in the enlarging myocardium. The analysis of population of replicative intermediates of mtDNA have shown dramatic decrease in the frequency of D-loops in preparations obtained from hypertrophied hearts. This observation indicates that the increase in replicative flux of mtDNA is associated with the removal of a block in the conversion of D-loops to other intermediates.
在成年雌性大鼠主动脉缩窄后，对线粒体增殖进行了研究。采用荧光法测定线粒体DNA（mtDNA）。通过评估DNA的分子构象，建立并验证了去除核DNA的条件。术后2天、4天和7天，线粒体中mtDNA浓度分别增加了11%、72%和117%。与细胞色素c、b和aa3的积累速率比较表明，在心脏扩大的最初24小时内，线粒体内成分的积累比mtDNA快，但在随后的六天里，mtDNA增加的速率远远超过细胞色素的增加速率。这些数据表明，可用的mtDNA模板数量不是调节心肌肥大中转录和翻译过程的唯一因素。对mtDNA复制中间体群体的分析表明，从肥大心脏获得的制剂中D环频率显著降低。这一观察结果表明，mtDNA复制通量的增加与D环向其他中间体转化的障碍消除有关。
